Apple is replacing some iPad2 units due to a problem with their 3G wireless Internet network technology.

The units, which use Verizon’s 3G network, were equipped with duplicate mobile equipment identifiers, or MEIDs, which enable the devices to connect to the network. If a device has a duplicate MEID, it cannot connect.

A spokesperson for Apple said the duplicate MEIDs were installed on an “extremely small number of iPad2 units for the Verizon 3G network.”

Apple will replace the problematic units, which went on sale in March, with new ones.

Aside from the replacement, Apple has otherwise had a smooth launch of the iPad2, which updated the initial version of the tech giant’s iPad mobile computing device launched in early 2010. More than 300,000 sold on their first day.

Shortly after the launch, though, Apple acknowledged that “a very small number” of iPad users had problems connecting to Wi-Fi and offered remedies on its support Web site.